Hue: Failed to access filesystem root

Reaz picture Reaz · Feb 3, 2016 · Viewed 7.8k times · Source

I'm using Hue 3.9 with a Hadoop 2.6.2 cluster. The computers all have Ubuntu 14.04. I was able to successfully install Hue, but it does appear to have a few errors when viewing hue from the web UI. I'm trying to solve these issues one at a time, so I'm really only concerned with the first issue for right now:

hadoop.hdfs_clusters.default.webhdfs_url    Current value: http://localhost:50070/webhdfs/v1
                                            Failed to access filesystem root

Here is a picture of Hue and the errors associated

I've been looking this error up for a while and I cannot figure out why it fails to access. I'm thinking the solution might show itself in the hue.ini configuration file, but I've yet to find anything of use in the file. I specified the user "hduser" in the file as well and hduser is a member of sudoers on the machine.

Any help is appreciated!

Answer

Stefan Papp picture Stefan Papp · Feb 4, 2016

HDFS is using ACLs to access the filesystem. If you perform a "HDFS DFS -LS" on your cluster, you will see owners and access rights similar to a Linux file system.

The Hue service is executed with a service user. Per default, this user is called "hue". This can be changed in the hue.ini. Comments on the configuration are self-explanatory. Look for "# Webserver runs as this" user (https://github.com/cloudera/hue/blob/master/desktop/conf.dist/hue.ini

You have two options to solve the problem: * Authorise your HUE user to access all HDFS paths with ACLs (e.g. give the service user ownership over the objects in HDFS. * Or better: Make sure that use can impersonate this users by adding

 <property>
      <name>hadoop.proxyuser.hue.hosts</name>
      <value>*</value>
 </property>
 <property>
      <name>hadoop.proxyuser.hue.groups</name>
      <value>*</value>
 </property>

to hdfs-site.xml